EXHIBIT 10.21






AMENDMENT TO LOAN AGREEMENT AND SECURITY AGREEMENT


         This Amendment to Loan Agreement and Security  Agreement  ("Amendment")
made this 29th day of June,  1995 by and between Unigene  Laboratories,  Inc., a
Delaware  corporation  authorized to do business in the State of New Jersey (the
"Borrower") with offices at 110 Little Falls Road, Fairfield, New Jersey and Jay
Levy,  Warren P. Levy and Ronald S. Levy, all with offices located at 110 Little
Falls Road, Fairfield, New Jersey, individually (jointly the "Lender").
         WHEREAS,  the parties have previously entered into a Loan Agreement and
a Security Agreement both dated March 2, 1995 pursuant to which Lender loaned to
Borrower  certain sums not to exceed at any time the amount of  $500,000.00  and
Borrower granted to Lender a security interest in certain  collateral located in
premises known as 83 Fulton Street,  Boonton,  New Jersey leased by the Borrower
as particularly  described therein (the "Collateral"),  which Loan Agreement and
Security Agreement have been amended by the Borrower and the Lender by Amendment
to Loan  Agreement  and  Security  Agreement  dated  March 20,  1995 (the  "Loan
Agreement" and the "Security Agreement"; and
         WHEREAS,  Lender  has  previously  loaned  to  Borrower  the  amount of
$255,000.00 in addition to amounts loaned  pursuant to the Loan Agreement and is
unwilling  to lend to Borrower  any  additional  sums unless and until  Borrower
grants to Lender a security  interest in the  Collateral to secure the repayment
of all such additional loans including the prior loan of $255,000.00; and
         WHEREAS,  Borrower  desires to arrange for additional  borrowings  from
Lender in the amount not to exceed $445,000.00; and

         NOW,  THEREFORE,  in  consideration  of  the  mutual  covenants  herein
contained and other good and valuable consideration,  receipt of which is hereby
acknowledged, the parties agree as follows.
1.       ADVANCES
         The term  "Loan" as that term is set  forth in the Loan  Agreement  and
Security Agreement shall be revised to reflect the $500,000.00 borrowing ("Prior
Loan") and the additional  borrowing of $255,000.00  and subsequent  loans in an
amount not to exceed at any time  $445,000.00  (the total of (X) $255,000.00 and
(Y) $445,000.00 being herein referred to as the "New Loan".)
         a. The New Loan  shall be and is hereby  made  subject to the terms and
conditions  of  the  Loan  Agreement,   and,  provided  no  event  or  condition
constituting  a default or an event of default has  occurred,  Lender shall lend
and re-lend to Borrower from time to time until the  termination  date,  amounts
which  shall  not  exceed at any one time in the  aggregate  the New Loan in the
principal amount of Seven Hundred Thousand ($700,000.00) Dollars.
         b.  Advances of the New Loan shall be made to the  Borrower  under this
Agreement and delivered to the Borrower by check payable to the Borrower or wire
transfer of funds for credit to any general  deposit  account  maintained by the
Borrower, as the Borrower may reasonably direct.
         c. The Borrower  acknowledges  receipt pursuant to this Agreement prior
to the date hereof of sums  totalling Two Hundred Fifty Five Thousand and 00/100
($255,000.00)  dollars,  which  advances have been made pursuant to the terms of
this  Agreement  and  shall  be  evidenced  by the  Promissory  Note to be given
pursuant hereunder.

2.       COLLATERAL
         In consideration of the Lender's  granting to the Borrower the New Loan
in accordance  with the terms and  conditions of this  Agreement,  and to secure
payment  and  performance  of the  obligations  of the  Borrower  to the  Lender
hereunder and the Promissory  Note to be delivered  pursuant to this  Agreement,
the Borrower  hereby  amends the Security  Agreement and grants to the Lender to
secure  the  promissory  note to be given to  evidence  the New Loan a  security
interest in the  Collateral.  The Security  Agreement shall remain in full force
and effect  until all  obligations  of the Borrower to the Lender are fully paid
and satisfied.
3.       DOCUMENTATION
         Upon the execution  hereof Borrower shall execute and deliver to Lender
the following  documents:  (i) Promissory Note; (ii) Financing Statements (2) to
be filed in the Morris County Clerk's Office and in the New Jersey  Secretary of
State's  Office;  and  (iii) an  Affidavit  of Title  as to the  Collateral.  In
addition to the foregoing,  upon the execution  hereof Borrower shall deliver to
the Lender (vi) a certified  copy of the resolution of the Board of Directors of
the Borrower authorizing  execution,  delivery and performance of this Agreement
and the Promissory  Note.
4.       ADDITIONAL  ADVANCES
  Lender's  obligation to make
additional  advances  hereunder shall be conditioned  upon and is subject to the
satisfaction  of the following  conditions  precedent:  1.  Borrower  shall have
complied  with and shall then be in  compliance  with the terms,  covenants  and
conditions of this Agreement and all of the loan documents  pursuant hereto.  2.
There  shall  exist no default or even of default.  3. The  representations  and
warranties  contained  in  any  document  given  pursuant  aid  this  Agreement,
including the  Affidavit of Title,  shall be true and with the same effect as if
those representations and warranties had been made at the time of making of each
advance.
5.       MISCELLANEOUS
         All  representations,  covenants and  warranties  contained in the Loan
Agreement,  except  as  otherwise  herein  provided,  are  reaffirmed  as of the
execution of this  Agreement and shall be binding upon the  Borrower.  Except as
otherwise provided, all terms and conditions of this Loan Agreement shall remain
in full force and effect,  shall be binding upon the Borrower and the applicable
to the New Loan.


         IN WITNESS  WHEREOF the parties have executed the within Loan Agreement
the day and year first above written.

Attest:                                                    Borrower:
                                                   Unigene Laboratories, Inc.


                                          By
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 Ronald S. Levy, Secretary                        Warren P. Levy, President
(Seal)


Witness:                                                      Lender:


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                                                              Jay Levy



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                                                              Warren P. Levy



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                                                              Ronald S. Levy